Process of making color photographic transparencies.



A. HERNANDEZ-MEJVIA.

.Y PROCESS 0F MAKING COLOR PHOTOGRAPHICKTRANSPARENCIES.

APPLICATION HLED JUNE 21. 191.2.

1,174,144. Patented Mar. 7, 1916.

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ARTURO HERNANDEZ-MEJIA, 0F ROCHELLE, NEW YORK.

PROCESS OF MAKING COLOR PHOTOGRAPHIC TRANSPARENCIES.

To all whom t may concern Be it known that I, ARTURO HERNANDEZ- MEJIA, a citizen of the` Republic of Venezuela, residing at 6 Alpha Place, New Rochelle, county of Westchestenand State of New York, have invented certain new and useful Improvements in Processes of Making cies, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to certain methods of producing transparencies which, projected from a lantern or motion-picture machine, will reproduce upon a suitable screen or plain surface, the image photographed, in approximately the colors of nature. s

The invention has for its object the production of transparencies either singly, or in films or ribbons which can be used for projection by any ordinary lantern or mov- 'ing-picture machine without alteration of such machines, and without the use of special mechanism or contrivances, or of more than one lantern or moving-picture machine for said projection, and which will reproduce approximately the colors of nature without the aid or separate process of handcoloring or machine stenciling.

In the followingdescription, merely for illustration, I have suggested certain colors andcombinations of colors; but it is obvious that. in practice any suitable Vcolors may be used. The steps necessary to carry out the invention will be readily understood from the following description. n

The invention will be understood by reference to the annexed drawing, in which- Figure l is a diagrammatic section of the plate, film or ribbon embodying the invention; Fig. 2 represents a strip of the blank or unprinted film with different layers broken away; Fig. v3 shows a strip of moving-picture film with images printed from the prepared negatives, and colored, a portion of the rear side being represented as turned into View; Fig. 4 represents a portion ofthe same film after the complementary colors are formed upon such printed images; Fig. 5 shows a green-screeny negative, a red-screen negative, and a positive printed from such negatives. Fig. 6 shows a lantern-slide; Fig. 7 shows portion of a film with the printed 'coating broken away; Fig. 7a represents a portlon Color Photographic Transparenq Specification of Letters Patent.. Ptented Mal- 19160 Application led June 21, 1912. Serial No. 705,095. I i

of the same film withv a part of the same b roken .away to the coating upon the rear side; Fig. 8 represents the picture viewed through the film of Fig. 7a; and Fig. 9 is a dlagrammatic section like Fig. 1, of a iilm havlng the body and coating supplied with complementary colors.

Similar letters refer to similar parts throughout the several views.

In Figs. l and 2, a is the body of the transparent supporting means, such as a plate, iilm or ribbon. b and b are coatlngs of gelatin, collodion, or other substance upon the opposite sides of the body a, to hold the sensitizing agent. These figures show the blank film merely sensitized, c, c representing the layers of sensitizing material. The layers a, b, 8:0.,` are broken away t expose the ones in the rear. l

Fig. 3 shows a portion of a finished film` with one end folded over to show the opposite side, to present two views A and B of a flag, for contrasting the complementary colors upon the opposite sides of the film, each view showing only the color on the side exposed, in proportion to the separal in proportionate relation to the separation of color aected by the screens. Fig. lY shows that the views A and B on -the opposite sides of the film are in register with one another, all the assumed layers of the film, excepting the gelatin and image upon the rear side beingbroken away to exhibit such condition. The opposed views are compementarilv colored.

Fig. 5 shows a negative g taken through a green-screen, a negative h of the same object taken through a red-screen, and a positive lm z' printed from these negatives previous to any coloring of the images. In the negative g, the body of a parrot is shown with dense shading g in some parts, while the corresponding area it in the negative la, shows a blank or lack of density, while the birds wing f1.2 in negative h, shows density, and the corresponding space g2 in the negative g shows a blank or lack of density. In

the positive, z, while only one side is shown, it represents the combined ei'ects of the printing from both negatives, as if viewed in front of a light.

Fig. 6 shows a lantern-slide, j, consisting of a double coated transparent support having opposite sides printed from negatives of the same object, taken through complementary screens, and coloredV as described herein. Such slides are usually mounted between cover glasses and bound together.

Fig. .7 shows a lm with the nearest layer c bearing an image c5 colored red and broken away to show a yellow tinted body a., and the registration with the image c* on the opposite side, which at the stage shown is uncolored.

Fig. 7'a shows the same view after the opposite image c has been colored blue.

Fig. 8 shows the composite picture viewed from the film of Fig. 7a. 4

Fig. 9 sho-ws a film in section with the various layers colored, as could be used,`

when it might be desirable to photograph special subjects, requiring a preponderance of some color.

'The body a is hatched to-conventio-nally represent the color yellow'. The ima-ge c2 upon one side may be changed to a blue color by suitable toning or developing solutions, and the gelatin coating b or b dyed v a different color as green or purple or left unchanged, as may best suit the general tone of the picture which is being reproduced. When one image c2 is of a blue color, the image 03 upon the opposite side may be changed by'chemical action such as toning or developing to a red or Vcrimson color. In such case, the gelatin coating which carries such red image may' be dyed a different color, if desirable, or left unaltered or free from dye.

It is obvious that any of the well known` methods or combinationof colors for coloring gelatin or silver deposit before, during or after development, can be used to produce these color films. With such combinations, the picture formed by Vthrowing light through such a film upon a white screen will be shown in colors s'ui'ciently like those of nature to give an impressionto the eye of an exact reproduction in colors of the original object.

I have obtained good results by converting the silver ,salts into compounds of various metals, for instance, into silver iodid bv im- 1 mersing in potassium-iodid solution, then immersing in a basic dye, and then dissolving the silver iodiol, leaving a` dyed image in the clear gelatin, the colors of the dyes being varied upon each sideI of the plate or film in complementary relation to one another; that is to say, the image on one side which has been obtained from the negative through the red screen will be dyed witha green dye,

or chemically changed to green, and the image on the other side which has been obtainedl from the negative through the green screen will be dyed with a red dye, or-

, may be taken through a green screen and the other through a red screen. A suitable .printing machine is then used to accurately register the two negatives thus taken, and

to simultaneously embrace between the negatives a specially prepared positive film coatedon both' sides with a substratum or support, as gelatin, and a' sensitive emul-4 sion. The green-screen negative .and the l red-screen negative are thus held close to the unexposed opposite sides of the sensitized film, and the whole is then so exposed that light strikes on both sides simultaneously and a positive transparency, after development, is thus vobtained with corresponding images upon both sides of the doubly coated film. The film will have on one side the impressionprinted from the green-screen negative, and after or during. develo-pment and fixing, the printed image on that side is rendered red by chemical action, as shown in the lower part of Fig. 3. The gelatin, or substratum, on that side is, if desired, dyed with a contributory color-(as yellow) one which when combined in projection,.would be required with the 'red and green to make total opacity or black, a degree of coloring beingy employed which will' 'not permit the actinic light or will do so very sparingly, to pass through the lm tothe opposite side during the printing operation. Provision is made during the chemical operations for preventing the chemicals from action on the side opposite to the' one under treatment. Satisfactory coloring having been obtained on one side, the other side is treated .in a similar manner, the image obtained through the red-screen negative being reduced chemically to a blue-green color, complementary to the red-screen through which yit was taken. The gelatin or substratum on this side may also be dyed a contributorycolor, such as yellow. l

While theprocess of coloring each side by chemical means 1s explained in detail, as if I done first on one side and then on the other,

it is evident that in carrying out the inven-l change the silver salts to complementary colors are separately incorporated in the emulsion, each being put separately upon one side of the support, at the time of coating; for instance, copper salts, as cupricsulfate, on one side and iron salts, as ferric rhlorid, on the other, and the whole treated with a restrained potassium ferricyanid solution, which uniting with the iron and 4silver salts on one 'side will form a blue iron and silver ferricyanid, and with the copper and silver salts on the other side will form a red,- copperand silver ferricyanid.

Upon examining the positive two-faced color film thus obtained, it is found that,

f where the subject photographed, a Venezuelan fiag for example, showed a red-bar, the green-screen side showed a strong red color on this bar, while the red-screen side showed little or no green, the intense red overcoming the light yellow on the substratum. In fact, if the red-screen has done its work properly there should be no color at all on the green colored side where the red-bar is photographed, excepting in the folds or shadows, andthere would be a correspondingly strong deposit of red, copper and silver salts upon the opposite side. Where the flag showed yellow, the green side of the film has' ay mezzo-tint of green which, viewed by holding it to the light, loses its blue components by the same being absorbed by the mezzo-tint of red on the opposite side, and there is imparted to the eye an impression of yellow1 aided by the yellov7 contributory color of the gelatin or substratum. Where the color of the flag is blue, a similar condition exists, blue-green is deposited on one side and correspondingly no red is deposited on the opposite side by the action of `the screens or filters and the dyes and chemical changes above described; thus giving the eye a distinctly vivid blue sensation, the deepness of the blue deposit completely overcoming the light yellow of the gelatin or substratum, if thus colored.

For the purpose of carrying out thisinvention, any two negatives of the same subject taken from the same point can be used, which are taken through complementary screens, separating the spectrum as evenly as possible; whether they have been taken by ordinary cameras in two exposures or with cameras arranged for taking two eX- posures at one time, by a lens or lenses arranged to takeviews from the same point.

I have, in practice, found the followlng the most effective method of obtaining negatives to carry out my invention: For this object, I use a camera having only one lens, provided with a reflector transparent enough to permit both the reflectlon and the passing through (refractlon) of the hghtrays. I utilize reflection to secure the negative to' be used in printing one slde of my two-faced coated film, ,and I use the transmitted light, that is to say, the direct rays, to produce the negative to be used in printing the other side of my two-faced coated film. The secondary image in the reflected used in the reiiector. In this manner, two negatives are obtained, reversed right and left with respect to one another, a condition that is undesirable in other methodsused for producing super-imposed color photographs or transparencies, but it is a distinct advantage where the images are to be printed on both sides of a two-faced coated film. Motion pictures, reproducing in colors the subjects or scenes photographed, have been publicly shown by methods which require expensive and elaborate apparatus, making them unsuitable for general adoption in most moving-picture theaters. This deprives the general public in country towns, schools, institutions, clubs, private houses, &c from the enjoyment of this most desirable achievement, the viewing of nature in its own colors through motion photography. In my invention, I succeed in producing one film in colors, which, (by coating it on both sides, and chemically coloring each side projecting apparatus, with ordinary or usual light` using the same speed of projecn tion as with ordinary black and white pictures, and without unusually darkening the room or theater where they are shown, and without providing the audience with any appliances for' viewing the image onl the screen.

' In my invention, the cost of producing colored motion or still photography is greatly reduced, as only the same amount of film and the same number of projections per second are necessary as with black and white films, and the volume -of electric current necessary for light and for operating the projector is not increased, nor is the cost of manufacture materially greater, because the amount of emulsion on both sides of the film is no greater than the alnount-now used on only one side. I

I am aware that photographic negatives,

'taken through colored screens, and separate j picture, is absorbed'by the color of the screen v loo ' point, respectively through screens of comwhich consists in simultaneously taking two negatives of the same subject, from the same plementary colors, one of said negatives being directionally reversed with respect -to the other, printing from one of said negatives upon one side of a single transparent positive film, sensitized on both sldes, and

p color.

2. The 'improved process of making a single color photographic transparency, or a series of color photographic transparencies in bands or films, for projection by direct or reflected light, which consists in simultaneously taking two negatives of the same subject', from the same point, respectively through screens of complementary colors, one of said negatives being directionally reversed with respect to the other, printing from one of said negatives upon one side of a single transparent positive lm or support, colored in a suitablemanner with relation to the colors of the images, photographically sensitized on both sides, and froml the other of lsaid negatives upon the opposite side of said positive film, with theJ images in register, treating one side of the positive so that the image thereon will appear in one of the primary colors, and treating the opposite side of said positive so that the corresponding image will appear in another and complementary primary color, the color of the support being the third primary color.

3. The improved method of 4making a color photographic transparency, which consists in taking two negatives of the same subject,` from the same point, respectively through screens of complementary colors,`

one of said negatives being directionally reversed with respect to the other, printing from one of said negatives upon one side of a single transparent positive film, photographically sensitized on both sides, and from the other of said negatives upon the opposite side of said positive film, with the images in register, treating one side of the positive so that the image thereon will appear in one color, and treating the opposite side of said positive `so .that the corresponding image will appear in a complemen' ary color.

4. The improved method of making a color photographic transparency, which consists in'taking two negatives, respectively through screens of complementary colors, one of said negatives being directionally reversed, with respect to the other, printing fromone of said negatives upon one side of a single transparent positive support or film sensitized on both sides, and from the other of said negatives upon the opposite side of said film, with the images in register, treating one 'side of the positive so that the image thereon will appear in one color, and treating the opposite side of said positive so that the 'image on that side will be colored in la complementary color, and dyeing the support of the sensitizing emulsion on at least one side with a color which will supplement the other` colors.

5. The improved method of making a color photographic transparency, which consists in taking two negatives of the same subject respectively through screens of complementary colors, printing from one of said negatives in contact, emulsion: to emulsion, upon one side of a single transparent positive support or film sensitized on bothsides,

and -from the other of said negatives printing on the transparent support, directionally reversing the image with respect to the other negative upon the opposite side of said film, the images beingv registered permanently, treating one side of the positive so that the image thereon will appear in one color, and treating the other side of the positive so that the image on that side will appear in a complementary color, the support or film thus lobtained containing permanentlyl superposed images forming a composite color picture for projection or viewing by direct or reflected light. ARTURO HERNANDEZ-MEJIA.

Witnesses:

Gno.' H. RACHE, J. S. MAXWELL. 

